Some surgical planning and navigation systems allow for preoperative identification of target areas within patient tissues. Some systems also allow for the preoperative identification of trajectories for surgical instruments to reach the above-mentioned target areas. However, particularly in the case of tissue resection procedures, current planning and navigation systems are unable to provide medical staff with confirmation that the planned target areas have been fully resected. Instead, such confirmation is generally provided via manual sampling of resected tissue, for example by a pathologist. Such sampling may not be completed in time to correct the surgical procedure if some target tissue has not been resected, and in addition the sampling may be prone to errors.